My 2 cents:
Firstly, psychology is a very broad term in itself. Within psychology, you can have a more cognitive approach or you can focus on social interactions and behavior. If you go into the social and behavioral psychology, then this is almost completely under the branch of a social science, which in layman's understanding is not a science. If you go into a more cognitive program, and are dealing with the scientific method (especially when you involve imaging, EEG, etc), you are dealing with a science - this is undeniable.
And here is what I think for your situation:
As a premedical student, and a student in general, its important to (a) study and do well in what you really enjoy and (b) obtain a fund of knowledge that is based in hard sciences for your pre-medical requirements. Here are some things to consider in your decision making:
1) A high GPA in neuroscience/neurobiology is far more impressive than one in psychology (which is typically regarded as an easier major)
2) If the program you are entering is well breadthed, the study of neuroscience will encompass not only the biological aspects to neuroscience, but will also cover aspects of cognitive and behavioral psychology as it pertains to more global aspects of the brain. Depending on your program, you can partake in more electives in this area while completing the necessary biological aspect of it, thus giving you a more psychology feel to it.
If still indecisive, I would go with the neuroscience major, psychology minor. This way everyone's happy!